Cohort | Inclusion | Clinical | Serological | Morphological | Positive in all three domains | Treatment | Outcomes (IPAF versus other entities) |
Jee et al. [25] | IIP, CTD-ILD, unclassifiable ILD n=228 IPAF 36 IIP 113 CTD-ILD 49 Unclassifiable 30 | 61.1% Arthritis 38.9% Raynaud's 25% Mechanic's hands 5.6% | 83.3% ANA 16.7% RF/CCP 16.7% SSA 0% MA 44.1% ASA 35.3% ANCA 20% | 86.1% Radiology NSIP 44% OP 19.4% NSIP/OP 16.7% UIP 16.7% Histology (available in 19.4%) UIP 73.5% NSIP 22.9% | 30.6% | Any 83.3% IS 80.6% Antifibrotic 2.8% | TFS IIP worse versus CTD IPAF no different versus IPF or CTD-ILD PFS No difference between groups |
Oldham et al. [41] | IIP or UCTD n=422 IPAF 144 | 49.3% Raynaud's 27.8% Arthritis 17.4% Mechanic's hands 10.4% | 91.7% ANA 77.6% RF 13% CCP 4.7% SSA 16.6% ASA 0.7% | 85% Radiology NSIP 31.9% OP 16.9% NSIP/OP 3.6% UIP 54.6% Histology (available in 57.6%) UIP 73.5% NSIP 22.9% | 49.3% | IS 32.2% | IPAF survival worse than CTD-ILD; trend towards better than IPF Non-UIP IPAF similar to CTD-ILD; UIP-IPAF similar to IPF |
Chartrand et al. [24] | Autoimmune ILD without CTD n=56 IPAF 56 | 62.5% Raynaud's 39% Arthritis 16.1% Mechanic's hands 28.6% | 91.1% ANA 48.2% CCP 10.7% RF 10.7% SSA 42.9% ASA 36% | 98% Radiology NSIP 57% OP 7.1% NSIP/OP 14.3% LIP 1.8% UIP 8.9% Histology (available in 64.3%) NSIP 33% UIP 22% | 52% | IS 98.2% CS 81.8% CS+IS 76.4% | No deaths reported |
Ahmad et al. [26] | Hospitalised with IIP or CTD-ILD n=380 IPF 156 CTD-ILD 167 IPAF 57 | 47.3% Raynaud's 75% Arthritis 48.1% Mechanic's hands 7.4% | 93% ANA 82% RF 7.5% CCP 9.4% SSA 9.4% ASA 17% | 78.9% Radiology NSIP 53% OP 3.5% NSIP/OP 15.8% LIP 1.8% UIP 28% Histology (available in 28.1%) NSIP 31% UIP 19% | Not reported | IS 28.6% CS 67.9% Antifibrotic 5.4% | IPAF survival not different to IPF |
Ito et al. [20] | IIP, serological and morphological domains met n=98 IPAF 98 | Not reported | 100% ANA 28.6% RF 28.5% CCP 15.3% SSA 18.4% ASA 13.3% | 100% Radiology NSIP 64.3% OP 20.4% NSIP/OP 15.3% Histology (available in 17.3%) NSIP 20.6% OP 5% NSIP/OP 20% UIP 3.1% | Not applicable | CS 27.6% CS+IS 44.9% | Not applicable |
Dai et al. [46] | All ILD n=1429 IPAF 177 Other ILDs 252 | 20.3% Raynaud's 12.9% Arthritis 4.5% Mechanic's hands 1.7% | 92.1% ANA 49.2% RF 12.4% CCP 5.6% SSA 36.1% ASA 3.9% | 95.5% Radiology NSIP 61.6% OP 22% NSIP/OP 11.9% UIP 4.5% | Not reported | CS 72.3% | IPAF worse survival than non-IPAF |
Yoshimura et al. [47] | Chronic fibrotic ILD n=194 IPF 163 NSIP 31 IPAF 32 | 53.1% Arthritis 28.1% Raynaud's 18.8% Mechanic's hands 12.5% | 71.9% ANA 28.1% RF 21.9% CCP 9.4% SSA 9.4% ASA 6.3% | 96.9% Radiology NSIP 40.6% NSIP/OP 12.5% Histology NSIP 59.4% | 21.9% | CS 59.4% IS 34.4% Antifibrotic 25% | IPAF survival better than non-IPAF IPAF-NSIP better survival than non-IPAF-NSIP IPAF-NSIP and IPAF-IPF similar outcomes |
Kelly and Moua [44] | Defined UCTD-ILD n=151 IPAF 101 IPF 50 | Not reported Raynaud's 54.5% Arthritis 29.7% Mechanic's hands 10.9% | Not reported ANA 18.8% RF 18% CCP 3.8% SSA 35.6% ASA 1% | Not reported Radiology NSIP 64.4% OP 3.9% NSIP/OP 4% LIP 2% UIP 11.9% Histology (available in 50.5%) NSIP 13.7% UIP 23.5% OP 23.5% Non-diagnostic 37.2% | Not reported | Not reported | IPAF survival better than IPF IPAF-UIP worse survival than IPAF-non-UIP IPAF-UIP similar to IPF |
Lim et al. [48] | All ILD n=305 IPAF 54 CTD-ILD 76 IPF 175 | 31.5% Raynaud's 17.6% Arthritis 76.5% Mechanic's hands 5.9% | 90.7% ANA 63.3% RF 28.6% CCP 14.3% SSA 8.2% | 81.5% Radiology NSIP 63% OP 7.7% NSIP/OP 5.1% UIP 25.9% | Not reported | Not reported | IPAF survival better than IPF, worse than CTD-ILD |
ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; ASA: anti-synthetase autoantibodies; CCP: cyclic citrullinated peptide; CS: corticosteroid; CTD: connective tissue disease; CTD-ILD: connective tissue disease-associated interstitial lung disease; IIP: idiopathic interstitial pneumonia; ILD: interstitial lung disease; IPF: idiopathic pulmonary fibrosis; IS: immunosuppression; LIP: lymphocytic interstitial pneumonia; MA: myositis autoantibodies; NSIP: non-specific interstitial pneumonia; OP: organising pneumonia; PFS: progression-free survival; RF: rheumatoid factor; SSA: Sjögren syndrome-related antibody A; TFS: transplant-free survival; UCTD: undifferentiated connective tissue disease; UIP: usual interstitial pneumonia. Reproduced and modified from Jee et al. [25] with permission.